This invention relates to rocket propulsion systems. More particularly, this invention relates to a throttleable rocket engine.
FIG. 1 is a schematic of a rocket propulsion system 100. The system 100 includes a rocket engine 101. A fuel pump 103 supplies fuel to the rocket engine 101 from a fuel supply 105. Likewise, an oxidizer pump 107 supplies oxidizer to the rocket engine from an oxidizer supply 109. The rocket engine 101 combines the fuel and oxidizer, and ignites the mixture in a combustion chamber (not shown). The exhaust 111 exits a nozzle (not shown) to produce thrust.
To provide the amount of fuel and oxidizer required by the rocket engine 101, pumps 103, 107 are preferably turbopumps. FIG. 2 is a schematic of a turbopump assembly 107. Generally speaking, the turbopump assembly 107 includes a turbine 113 connected to an impeller 115 by a shaft 117. The turbine 113 converts the kinetic energy from an exhaust stream 119 into shaft horsepower to drive the impeller 115.
The impeller 115 transports the oxidizer from the supply 109 to the rocket engine 101. Turbopump 103 for the fuel operates in a similar manner, and is not described in further detail.
In conventional operations, the turbopumps 103, 107 provide a constant supply of oxidizer and fuel to the rocket engine 101. This uniform supply of oxidizer and fuel by the turbopumps 103, 107 produces a constant thrust in the rocket engine 101.
It is an object of the present invention to provide a rocket engine having adjustable thrust.
It is a further object of the present invention to provide a turbopump assembly that can adjust the thrust of a rocket engine.
It is a further object of the present invention to provide a turbopump assembly having a gas generator having a mixer section that can adjust output flow.
It is a further object of the present invention to provide a gas generator with a catalyst bed section that decomposes a material upon exposure to a catalyst and a mixer section that decomposes the material without exposure to a catalyst.
It is a further object of the present invention to provide a gas generator with a catalyst bed section that decomposes a material upon exposure to a catalyst and a mixer section that thermally decomposes a material without exposure to a catalyst.
It is a further object of the present invention to provide a gas generator having a catalyst bed assembly and which bypasses a portion of a material around the catalyst bed section for cooling.
These and other objects of the present invention are achieved in one aspect by a rocket propulsion system, comprising: a rocket engine; and a turbopump supplying fuel or oxidizer to the rocket engine. The turbopump can supply an adjustable flow of the fuel or oxidizer to throttle the rocket engine.
These and other objects of the present invention are achieved in another aspect by a turbopump assembly. The turbopump assembly comprises: a catalyst bed for decomposing a material to produce a discharge; a mixer section downstream of the catalyst bed for introducing an additional amount of the material to the discharge to produce an exhaust stream having a mass flow; a nozzle downstream of the mixer section; a turbine downstream of the nozzle; and a pump driven by the turbine. The additional amount of the material is selected to produce a desired amount of mass flow.
These and other objects of the present invention are achieved in another aspect by a method of throttling a rocket engine. The method comprises the steps of: providing a catalyst bed; introducing an amount of a material into the catalyst bed so that the catalyst bed decomposes the material to produce a discharge; and selectively adding an additional amount of the material into the discharge to produce an exhaust stream having a mass flow. The additional amount of material increases the mass flow of the exhaust stream.